1. Field of Invention
The present invention relates to an electron beam apparatus for irradiating a specimen to be inspected with an electron beam, and an inspection apparatus and inspection method for inspecting the specimen by the use of this electron beam apparatus.
2. Related Background Art
As is generally known, an electron beam apparatus for irradiating the specimen with an electron beam is equipped with an electron gun and electron optical system (electron lenses, etc.). In the electron beam apparatus, the electron beam discharged from the electron gun is applied on the specimen surface via the electron-optical system.
For an example of the equipment incorporating this electron beam apparatus, a description will be made on a scanning electron microscope (SEM) and electron beam inspection apparatus (EB inspection apparatus). By the way, to the SEM and EB inspection apparatus, a mechanism for detecting secondary electrons generated from the specimen by irradiating a specimen with an electron beam and creating a specimen image is incorporated.
To acquire the specimen image in SEM, the specimen is held stationary and the specimen surface is two-dimensionally scanned with the electron beam squeezed in the form of spot (spot beam). Consequently, SEM is popularly used for observing a comparatively small region (defect portion, etc.) of the specimen surface. The inspection of the whole specimen surface by SEM is not realistic due to its slow throughput.
As against this, the EB inspection apparatus has been under development in recent years in order to satisfy the requirements of inspecting a comparatively wide area or the whole area of the specimen surface.
For example, in the Japanese Patent Application Laid-Open(JP-A) No.7-249393 or in the Japanese Patent Application Laid-Open(JP-A) No. 10-197462, there are disclosed EB inspection apparatus in which by scanning the specimen surface with the electron beam shaped in the form of a rectangle (rectangle beam) while the stage is being continuously moved, the specimen image is obtained.
In addition, in the Japanese Patent Application Laid-Open(JP-A) No. 10-294345, there is disclosed an EB inspection apparatus which acquires the specimen image by continuously moving the stage in one direction and allowing the spot beam to scan the specimen surface in the direction crossing at right angles the one direction mentioned above.
In these EB inspection apparatus, since the specimen image is acquired while the stage is being moved, the specimen image is able to be taken in continuously from a comparatively wide area or the whole area of the specimen surface. Consequently, the EB inspection apparatus is able to inspect the specimen surface at an incomparably higher speed than that of the whole surface inspection by SEM.
In addition, in the above-mentioned EB inspection apparatus, the inspection speed is able to be increased as much as the stage moving speed is increased.